David Dobbs examines why the swine flu seems to be more deadly in Mexico.
Excerpt: Two weeks ago, no one had heard of this strain of swine flu. Now it's on every front page and almost every continent. Is this the deadly global pandemic we've been worrying about?
Certainly there's cause for sober concern, if not alarm. For of the two qualities vital to a nasty pandemic-to spread readily and to be deadly-this flu, a brand-new strain of swine flu, or H1N1, seems to possess the first: Evidence is strong that it spreads readily among humans. In that sense, it's an inversion of the bird flu.